#include<stdio.h>

int main(void) {
    int year, month;
    printf("Enter year and month: ");
    scanf("%d%d", &year, &month);

    switch (month) {
        case 4:
        case 6:
        case 9:
        case 11:
            printf("30\n");
            break;
        case 2:
            if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))
                printf("29\n");
            else printf("28\n");
            break;
        default:
            printf("31\n");
    }
}
